Hi, Greg KH: I am still not really understand why you said the driver looks like 8250. SP7021 SoC have our own register define. That's why we submit a new serial driver. Refer to: https://sunplus.atlassian.net/wiki/spaces/doc/pages/1873412290/13.+Universal+Asynchronous+Receiver+Transmitter+UART Regards, Hammer Hsieh hammer hsieh <hammerh0314@xxxxxxxxx> 於 2021年12月24日 週五 下午5:05寫道： > > Hi, Greg KH: > > 8250 driver means create driver in drivers/tty/8250/ ? > and current I create driver in drivers/tty/serial/ not correct ? > > Regards, > Hammer Hsieh > > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 於 2021年12月24日 週五 下午4:59寫道： > > > > On Fri, Dec 24, 2021 at 03:16:55PM +0800, hammer hsieh wrote: > > > Hi, Greg KH : > > > > > > In patch v1 coding quite mess, it is almost 2000 LOCs. > > > For down size code under 1000 LOCs, I decide to drop DMA function code > > > after patch v3. > > > I think that's the biggest difference compared with 8250. > > > Without DMA function, like you said it looks like 8250 variant. > > > I think I should put DMA function back in next submit. > > > > The 8250 driver handles DMA just fine today, why is your chip doing it > > differently? Are you sure it is a different chip? Who created a new > > uart chip these days? > > > > > Another question for why I need PORT_SLUNPLUS ? > > > I just check many other uart driver, almost all driver define their > > > own PORT number. > > > Actually, I didn't know about it. > > > Maybe some device like bluetooth(use uart port) need autoconfig. > > > Then it will call ioctl with TIOCSERCONFIG. > > > I don't have tool for calling type/config/request/release/verify. > > > > If you do not need it, and you can not test for it, please do not add > > it. > > > > thanks, > > > > greg k-h
